Los Angeles Chargers quarterback Philip Rivers (17) scrambles against the Seattle Seahawks in the first half of a pre-season NFL football game at the Stub Hub Center in Carson, Ca., on Saturday, Aug. 18, 2018. (Photo by Keith Birmingham, Pasadena Star-News/SCNG)

This should be old by now, but it isn’t. Even after hundreds of games, Philip Rivers still feels the novelty of preparing for an NFL season opener — the possibilities he envisions in the playbook, the cat-and-mouse game between offense and defense.

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“My hands were sweating a little bit,” the quarterback said Wednesday. He might not be quite as fired up as he was at 22, but he isn’t too far off.

Rivers is no longer the eldest statesman of the Chargers’ locker room, having ceded that title when 38-year-old tight end Antonio Gates re-signed earlier this week. But heading into his 13th season as a starter, the Alabama native remains the engine that powers this football team — one that, despite offseason hype, is still riding its longest playoff drought in 15 years.

A quick resume recap: Rivers has earned seven Pro Bowl selections, third-most among current quarterbacks; he has led the league in passer rating (in 2008), passing yards (2010) and completion percentage (2013); and perhaps most impressively, he has made 192 consecutive regular-season starts, more than any any other active player in the NFL.

Even compared to teammates a decade younger, Rivers’ enthusiasm stands out. The 36-year-old is still effusive when he talks about football, raving year-long about everything from offseason practices to the nuances of weekly game plans.

Sometimes, this catches people off guard. When receiver Tyrell Williams joined the Chargers undrafted rookie in 2015, what surprised him most about Rivers was “seeing how competitive and fiery he is throughout the week — not just on Sunday.”

His opponents often sound just as impressed.

“There’s something with the water down there,” said Kansas City coach Andy Reid, “because Philip Rivers keeps getting better.”

But for how much longer?

Rivers is only under contract with the Chargers through the 2019 season, though an extension next summer wouldn’t be surprising. He isn’t as accomplished as his peers from the 2004 NFL draft — Ben Roethlisberger and Eli Manning, who have each won two Super Bowls — but can make a credible argument for being the best quarterback in the class. Still, legacies are defined by trophies, and Rivers might only have a few more chances to get one.

In the midst of a five-win season in 2016, former Chargers running back LaDainian Tomlinson pushed for his old team to trade Rivers before hitting the restart button: “If you keep him there during this rebuilding process, you just wasted his entire career.”

That trade never happened. The Chargers fired Mike McCoy and replaced him with first-time head coach Anthony Lynn. The franchise moved from San Diego to Los Angeles, but kept half of the coaching staff — signaling their belief that the team only needed to be retooled rather than rebuilt.

The bet worked, at least in part. After four straight losses to open the 2017 season, Lynn rallied the Chargers to the cusp of the playoff picture, finishing the year with the NFL’s top passing offense and third-best scoring defense. That convinced many analysts that this is a supporting cast capable of maximizing Rivers’ talents.

Last month, for example, NFL Network’s Nate Burleson called the Chargers’ receiving corps the best in the league, noting the addition of a healthy Mike Williams to a crew led by Keenan Allen.

That sort of hype has gone unfulfilled before. One columnist floated a similar hypothesis in October 2014, asking whether or not Rivers — who threw for 1,756 yards in his first six games — was playing with his best group of pass-catchers yet.

By the end of that year, 18 teams had at least one 1,000-yard receiver. Five of those teams had a second. The Chargers finished with none. Rivers cooled off, throwing all but two of his 18 interceptions in his last 10 outings. His top four targets — including Gates and Allen, then in his second season — logged between 770 and 860 receiving yards.

This year’s Chargers could be the ones to truly scare opposing defensive coordinators. Another offseason together has given Lynn — a longtime running backs coach — a chance to better synthesize his offensive philosophies with those of coordinator Ken Whisenhunt. That, coupled with the signings of center Mike Pouncey and tight end Virgil Green, should improve the team’s bottom-10 rushing performance last season (99.7 yards per game).

The return of Mike Williams, last year’s No. 7 overall pick, is also invaluable. After struggling with back and knee injuries as a rookie, the 6-foot-4 receiver could help mitigate the loss of tight end Hunter Henry, who tore his ACL in May.

But everything still comes back to Rivers. The Chargers may have playmakers galore on both offense and defense, but that won’t matter if their quarterback doesn’t continue to play at a Pro Bowl level. He did that and more last season, looking rejuvenated after some early-season speed bumps.

In particular, Rivers took care of the ball, his 10 interceptions standing as his lowest single-season mark since 2009.

Six of those turnovers came against Kansas City. That turns Sunday’s game into an interesting hurdle for the Chargers, who have lost eight straight games in this division rivalry.

Kansas City is coming off back-to-back AFC West titles, but dramatically remade itself on both sides of the ball. Cornerback Marcus Peters, who picked off Rivers three times last season, has since joined the Rams. Starting safeties Eric Berry and Daniel Sorensen are both sidelined by injuries.

If the losing streak doesn’t end now, then when?

“Every season stands alone,” Rivers said. “I know it’s been a handful — we’ve had quite a few in a row on us, but this current team has never played these guys and vice-versa. They haven’t played us. That’s the way I like to look at it.”

Jack Wang covers the Chargers, the latest NFL team to relocate to Los Angeles. He previously covered the Rams, and also spent four years on the UCLA beat, a strange period in which the Bruins' football program often outpaced their basketball team. He is a proud graduate of UC Berkeley, where he spent most of his time in The Daily Californian offices in Eshleman Hall — a building that did not become earthquake-safe until after his time on campus.